/* =========================================================
   藏头诗生成器 - 样式表
   设计风格：中国风水墨（宣纸底色 + 朱砂点缀）
   布局：移动端优先，卡片式单页应用
   ========================================================= */

/* ---------- CSS 变量：统一管理主题色 ---------- */
:root {
  --color-bg: #f6f1e7;             /* 宣纸底色 */
  --color-bg-accent: #efe7d6;      /* 底纹色 */
  --color-surface: #fffdf8;        /* 卡片背景 */
  --color-primary: #b03a2e;        /* 朱砂红 */
  --color-primary-dark: #8e2f25;
  --color-text: #3b3228;           /* 墨色文字 */
  --color-text-light: #857a6b;     /* 次级文字 */
  --color-border: #e0d6c3;
  --color-error: #c0392b;
  --color-error-bg: #fdeeec;
  --color-success: #2e7d52;
  --radius: 12px;
  --shadow: 0 4px 20px rgba(59, 50, 40, 0.08);
  --font-poem: "Kaiti SC", "KaiTi", "STKaiti", "SimSun", serif; /* 诗句字体 */
}

/* ---------- 全局重置 ---------- */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* hidden 属性优先级最高，防止组件 display 规则覆盖导致元素意外显示 */
[hidden] {
  display: none !important;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  background-color: var(--color-bg);
  /* 淡雅底纹 */
  background-image: radial-gradient(var(--color-bg-accent) 1px, transparent 1px);
  background-size: 22px 22px;
  color: var(--color-text);
  line-height: 1.6;
  min-height: 100vh;
}

/* ---------- 页面容器 ---------- */
.page {
  max-width: 680px;
  margin: 0 auto;
  padding: 24px 16px 40px;
}

/* ---------- 顶部标题 ---------- */
.header {
  position: relative;
  text-align: center;
  margin-bottom: 24px;
}

.header__title {
  font-family: var(--font-poem);
  font-size: 2.2rem;
  letter-spacing: 0.15em;
  color: var(--color-primary);
}

.header__subtitle {
  margin-top: 4px;
  color: var(--color-text-light);
  font-size: 0.9rem;
  letter-spacing: 0.4em;
}

/* ---------- 卡片 ---------- */
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 28px 24px;
}

/* ---------- 表单 ---------- */
.form-field {
  margin-bottom: 18px;
}

.form-label {
  display: block;
  font-size: 0.92rem;
  font-weight: 600;
  margin-bottom: 6px;
}

.required {
  color: var(--color-error);
}

.form-input {
  width: 100%;
  padding: 11px 14px;
  font-size: 1rem;
  color: var(--color-text);
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.form-input:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(176, 58, 46, 0.12);
}

.form-input--invalid {
  border-color: var(--color-error);
}

/* 字段级错误提示 */
.form-error {
  margin-top: 6px;
  font-size: 0.82rem;
  color: var(--color-error);
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 9px 18px;
  font-size: 0.95rem;
  border: 1px solid transparent;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s, opacity 0.2s;
  user-select: none;
}

.btn:active {
  transform: translateY(1px);
}

.btn--primary {
  background: var(--color-primary);
  color: #fff;
}

.btn--primary:hover {
  background: var(--color-primary-dark);
}

.btn--ghost {
  background: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.btn--ghost:hover {
  background: rgba(176, 58, 46, 0.06);
}

.btn--block {
  display: flex;
  width: 100%;
}

.btn--large {
  padding: 13px;
  font-size: 1.08rem;
  letter-spacing: 0.2em;
}

/* 生成中的禁用态 */
.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
}

.btn--small {
  padding: 5px 12px;
  font-size: 0.82rem;
}

/* ---------- 加载指示器 ---------- */
.loading {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-top: 24px;
  padding: 18px;
  color: var(--color-text-light);
  font-size: 0.95rem;
}

.loading__spinner {
  width: 20px;
  height: 20px;
  border: 3px solid rgba(176, 58, 46, 0.2);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ---------- 错误信息区域 ---------- */
.error-box {
  margin-top: 24px;
  padding: 14px 16px;
  background: var(--color-error-bg);
  border: 1px solid #f2c4bd;
  border-left: 4px solid var(--color-error);
  border-radius: 8px;
  color: var(--color-error);
  font-size: 0.92rem;
  word-break: break-all;
}

/* ---------- 结果展示区域 ---------- */
.result {
  margin-top: 28px;
  padding-top: 22px;
  border-top: 1px dashed var(--color-border);
}

.result__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
}

.result__title {
  font-family: var(--font-poem);
  font-size: 1.15rem;
  color: var(--color-text-light);
  letter-spacing: 0.1em;
}

.result__body {
  font-family: var(--font-poem);
  font-size: 1.45rem;
  line-height: 2.3;
  text-align: center;
  letter-spacing: 0.12em;
  white-space: pre-wrap;
  word-break: break-word;
}

/* 每句藏头首字高亮为朱砂色 */
.result__body .head-char {
  color: var(--color-primary);
  font-weight: 700;
  font-size: 1.7em;
  vertical-align: -0.05em;
}

.result__line {
  display: block;
  animation: fadeUp 0.5s ease both;
}

/* 逐行渐入动画（通过内联 animation-delay 控制） */
@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ---------- 页脚 ---------- */
.footer {
  margin-top: 28px;
  text-align: center;
  font-size: 0.78rem;
  color: var(--color-text-light);
}

/* ---------- 轻量提示 Toast ---------- */
.toast {
  position: fixed;
  left: 50%;
  bottom: 48px;
  transform: translateX(-50%);
  background: rgba(59, 50, 40, 0.92);
  color: #fff;
  padding: 10px 22px;
  border-radius: 24px;
  font-size: 0.88rem;
  z-index: 999;
  animation: toastIn 0.25s ease;
}

@keyframes toastIn {
  from {
    opacity: 0;
    transform: translate(-50%, 8px);
  }
  to {
    opacity: 1;
    transform: translate(-50%, 0);
  }
}

/* ---------- 响应式适配 ---------- */
@media (max-width: 480px) {
  .page {
    padding: 16px 12px 32px;
  }

  .header__title {
    font-size: 1.7rem;
  }

  .card {
    padding: 22px 16px;
  }

  .result__body {
    font-size: 1.2rem;
    line-height: 2.1;
  }

  .result__body .head-char {
    font-size: 1.5em;
  }
}